Serious complications due to acute rhinosinusitis in children up to five years old in Stockholm, Sweden - Still a challenge in the pneumococcal conjugate vaccine era.

OBJECTIVES: The aim of this study was to analyze the rate of admissions, the rate of serious complications (postseptal orbital complications and surgery) and the bacterial etiology of acute rhinosinusitis in hospitalized children under five years old in Stockholm County, eight years after the introduction of the pneumococcal conjugate vaccine (PCV). The secondary aim was to compare this period with the period four years prior to the vaccine's introduction. METHODS: This was a population-based, descriptive observational study with retrospectively collected data from 1 July 2008 to 30 June 2016 in Stockholm County. Hospital admissions of children with a discharge diagnosis of rhinosinusitis and related complications were reviewed and compared to the pre-PCV period of 2003-2007. RESULTS: A total of 215 children were admitted, for a yearly incidence of 18.8 per 100 000 children (22.8 for boys, 14.6 for girls). Computer tomography-verified postseptal orbital complications occurred in 29 cases (13.5%) and surgery was necessary in nine (4.2%). Pathogens other than Streptococcus pneumoniae were found in the cases with postseptal complication or surgery (Streptococcus pyogenes in four, Haemophilus influenzae in three and Staphylococcus aureus in one case). In comparison to the four years pre-PCV, the incidence of admission decreased from 43.81 to 20.31 and 17.45 per 100 000/year for the two four-year periods after vaccine introduction. The incidence of CT-verified postseptal complication increased slightly from 1.51 to 2.34 and 2.74 per 100 000/year. The incidence of surgeries increased marginally but continued to be very low, from 0.22 to 0.54 and 1.03 per 100 000/year. CONCLUSIONS: Complications due to acute rhinosinusitis in children living in Stockholm County continues to be very rare after the introduction of pneumococcal vaccine. Hospitalization has decreased for children under five years old after PCV introduction, but the incidence or postseptal complications and surgery in the same population increased slightly. Predominantly bacteria other than Streptococcus pneumoniae was found. There is a need of larger studies to determine trends, and a need of prospective studies to elucidate the bacterial etiology, of serious complications due to acute rhinosinusitis in children.

Effects of Fission Yield Data in the Calculation of Antineutrino Spectra for

Fission yields form an integral part of the prediction of antineutrino spectra generated by nuclear reactors, but little attention has been paid to the quality and reliability of the data used in current calculations. Following a critical review of the thermal and fast ENDF/B-VII.1 ^{235}U fission yields, deficiencies are identified and improved yields are obtained, based on corrections of erroneous yields, consistency between decay and fission yield data, and updated isomeric ratios. These corrected yields are used to calculate antineutrino spectra using the summation method. An anomalous value for the thermal fission yield of ^{86}Ge generates an excess of antineutrinos at 5-7 MeV, a feature which is no longer present when the corrected yields are used. Thermal spectra calculated with two distinct fission yield libraries (corrected ENDF/B and JEFF) differ by up to 6% in the 0-7 MeV energy window, allowing for a basic estimate of the uncertainty involved in the fission yield component of summation calculations. Finally, the fast neutron antineutrino spectrum is calculated, which at the moment can only be obtained with the summation method and may be relevant for short baseline reactor experiments using highly enriched uranium fuel.

Diagnostic reference levels and patient doses in computed tomography examinations in Greece.

The purpose of this study is to present a national survey that was performed in Greece for the establishment of national Dose Reference Levels (DRLs) for seven common adult Computed Tomography (CT) examinations. Volumetric computed tomography dose index and dose-length product values were collected from the post-data page of 65 'modern' systems that incorporate tube current modulation. Moreover, phantom dose measurements on 26 'older' systems were performed. Finally, the effective dose to the patient from a typical acquisition during these examinations was estimated. The suggested national DRLs are generally comparable with respective published values from similar European studies, with the exception of sinuses CT, which presents significantly higher values. This fact, along with the large variation of the systems' dose values that were observed even for scanners of the same type, indicates a need for further patient protection optimisation without compromising the clinical outcome.

Efficiency of radiation protection equipment in interventional radiology: a systematic Monte Carlo study of eye lens and whole body doses.

Monte Carlo calculations were used to investigate the efficiency of radiation protection equipment in reducing eye and whole body doses during fluoroscopically guided interventional procedures. Eye lens doses were determined considering different models of eyewear with various shapes, sizes and lead thickness. The origin of scattered radiation reaching the eyes was also assessed to explain the variation in the protection efficiency of the different eyewear models with exposure conditions. The work also investigates the variation of eye and whole body doses with ceiling-suspended shields of various shapes and positioning. For all simulations, a broad spectrum of configurations typical for most interventional procedures was considered. Calculations showed that 'wrap around' glasses are the most efficient eyewear models reducing, on average, the dose by 74% and 21% for the left and right eyes respectively. The air gap between the glasses and the eyes was found to be the primary source of scattered radiation reaching the eyes. The ceiling-suspended screens were more efficient when positioned close to the patient's skin and to the x-ray field. With the use of such shields, the Hp(10) values recorded at the collar, chest and waist level and the Hp(3) values for both eyes were reduced on average by 47%, 37%, 20% and 56% respectively. Finally, simulations proved that beam quality and lead thickness have little influence on eye dose while beam projection, the position and head orientation of the operator as well as the distance between the image detector and the patient are key parameters affecting eye and whole body doses.

Image quality and patient dose in computed tomography examinations in Greece.

The purpose of this study is to evaluate image quality of various computed tomography (CT) scanners installed in Greece, as well as to investigate patient doses from common CT examinations. An image quality survey was performed in 44 CT scanners countrywide. The imaging performance of the systems was evaluated by measurements of certain parameters, such as image noise, spatial uniformity, high- and low-contrast resolution and slice thickness accuracy. Moreover, preliminary results of patient dose survey are presented. Concerning image quality, 80 % of the scanners were found to be in compliance with the national legislation and relative international guidelines for all the examined parameters. Weighted CT dose index and dose-length product values for chest and abdomen routine examinations were generally below the dose reference levels (DRLs) suggested by the European Commission. However, some scanners were found to deliver significantly higher doses than the suggested DRL for head routine examinations. Finally, differences in the performance among scanners of the same type and similar age were observed, pointing out the importance of frequent calibration, routine quality control and proper maintenance.

Education and training issues in individual monitoring of ionising radiation.

The present article deals with the education and training (E&T) issues of individual monitoring (IM) of ionising radiation, based on the requirements provided by the Basic Safety Standards Euratom Directive and the European Commission Technical Recommendations for IM of external radiation. The structure and the objectives of E&T programmes addressed to the staff of dosimetry services, in order to allow the recognition and ensure the continuity of expertise are discussed. The necessity for the establishment of a national strategy for building competence in IM through information, education, training and retraining programmes, addressed to the individually monitored personnel is underlined. The train the trainers' concept is recognised as being an important tool for optimising resources and transferring the skills necessary for building competence. The conditions under which an efficient train the trainers' approach can be established are discussed. Examples of curricula concerning the key persons involved in the provision of E&T in occupational radiation protection are also given.

Doses to operators during interventional radiology procedures: focus on eye lens and extremity dosimetry.

The present study is focused on the personnel doses during several types of interventional radiology procedures. Apart from the use of the official whole body dosemeters (thermoluminescence dosemeter type), measurements were performed to the extremities and the eyes using thermoluminescent loose pellets. The mean doses per kerma area product were calculated for the monitored anatomic regions and for the most frequent types of procedures. Higher dose values were measured during therapeutic procedures, especially embolisations. The maximum recorded doses during a single procedure were 1.8 mSv to the finger (nephrostomy), 2.1 mSv to the wrist (liver chemoembolisation), 0.6 mSv to the leg (brain embolisation) and 2.4 mSv to the eye (brain embolisation). The annual doses estimated for the operator with the highest workload according to the measurements and the system's log book were 90.4 mSv to the finger, 107.9 mSv to the wrist, 21.6 mSv to the leg and 49.3 mSv to the eye. Finally, the effect of the beam angulation (i.e. projection) and shielding equipment on the personnel doses was evaluated. The measurements were performed within the framework of the ORAMED (Optimization of RAdiation Protection for MEDical staff) project.

Educational and training activities in personal dosimetry in Greece.

An individual monitoring programme is one of the main components of any radiation protection programme since it constitutes the mean for assessing and thus optimising the doses of occupationally exposed workers. The Greek Atomic Energy Commission (GAEC) is the competent authority for radiation protection and nuclear safety in Greece. GAEC's educational and training activities in the field of occupational radiation protection at the national and regional (Eastern Europe) level are presented, along with the relevant activities of the University of Ioannina in the region of North-West Greece, as an example of a local education and training programme. The curricula of two postgraduate courses addressed to qualified experts and medical physics experts and mainly the modules dedicated to individual monitoring are discussed as well.

Quality of life for patients with schizophrenia living in the community in Greece.

Several quality of life instruments were considered for use in a Greek mental health environment. Subjective Quality of Life Profile was chosen as it was easy to complete and covered the issues raised by patients with schizophrenia through interviews. Confirmatory factor analysis gave credence to the four-dimensional structure identified by the original authors. Patients with schizophrenia were generally satisfied with their quality of life, found the items in the instrument important and were optimistic about expectations for change. Age, gender, education, marital status and years of sickness were not statistically significant in a general linear model with quality of life as the outcome for the 27 core questions. There were some statistically significant results for the three disease-specific questions; positive expectation was correlated positively with education and negatively with years of sickness.

Comparison of dose from radiological examination for scoliosis in children among two pediatric hospitals by Monte Carlo simulation.

The radiation exposures of children undergoing full spine radiography were investigated in two pediatric hospitals in Greece. Entrance surface kerma (Ka,e) was assessed by thermoluminescence dosimetry and patient's effective dose (E) was estimated by Monte Carlo simulation. All required information regarding patient age and sex, the irradiation geometry, the x-ray spectra, and other exposure parameters (tube voltage and current) were registered as well. Values of Ka,e were measured to range from 0.22 mGy to 2.12 mGy, while E was estimated to range from 0.03 mSv to 0.47 mSv. In general, all values were greater in one of the two hospitals, as higher tube currents and exposure times were used in the examinations because of the difference in radiographers' training and practice. Moreover, dose to red bone marrow was found to be between 0.01 to 0.23 mSv and dose to breast ranged between 0.02 and 1.05 mSv depending on the age, projection, and hospital. These values are comparable with literature sources.

Optimization of doses received by the hospital staff and the members of the family of patients undergoing 111In-DTPA-D-Phe1-Octreotide therapy.

According to the Euratom Directives (96/29, 97/43), the doses received by the workers as well as the family of patients and third persons during medical exposures, should conform to the dose constraint levels (DCLs), established by the authorities for each group in the context of optimisation. This study deals with the implementation of a radiation protection protocol, concerning the aforementioned group members for patients undergoing treatment with 111In-DTPA-D-Phe1-Octreotide, after intra-arterial infusion. It is shown that by applying this protocol the annual doses to the medical and technical staff are considerably reduced and remain below the established DCLs. Following the post-release behaviour instructions given to the patient, doses to the family and third persons may be kept lower than the corresponding DCLs provided by the National Regulations.

Occupational exposure in Greek industrial radiography laboratories (1996-2003).

More than 40 industrial radiography laboratories are operating in Greece using X-ray or gamma-ray sources and more than 250 workers occupationally exposed to ionising radiation in these facilities are monitored on a regular basis. This study presents the evolution of individual doses received by radiographers during the past years. The mean annual dose (MAD) of all workers as well as of exposed workers is estimated, and correlated to the types of laboratories and practices applied. The MAD of the exposed workers in industrial radiography is compared with the doses of workers in other specialties and with the doses of radiographers in other countries. Furthermore, the study attempts to propose dose constraints for the practices in industrial radiography, according to the BSS European directive and the relevant Greek radiation protection legislation. The proposed value was defined as the dose below which the annual doses of 75% of the exposed radiographers are expected to be included.

Discrimination of hip fractures by quantitative ultrasound of the phalanges and the calcaneus and dual X-ray absorptiometry.

The aim of the current study was to evaluate the ability of different techniques used for the assessment of bone status to discriminate between postmenopausal women with and without hip fracture. Fifty-one postmenopausal women (mean age 64.5 +/- 6.5) who had sustained a low energy hip fracture and 51 age-matched controls (mean age 64.6 +/- 6.0) were studied. Quantitative ultrasound (QUS) assessment was carried out using the Ubis 3000 device capable of measuring broadband ultrasound attenuation (BUA) and speed of sound at the calcaneus (SOSC) and the Sunlight Omnisense device capable of estimating speed of sound at the phalanges (SOSP). Femoral neck bone mineral density (BMD) was assessed using dual X-ray absorptiometry. Correlations between QUS variables ranged from r = 0.35 to 0.72 and between QUS variables and BMD from r = 0.30 to 0.36. BMD was the best discriminator of hip fractures (odds ratio = 3.61, area under curve = 0.824). All QUS variables were significant discriminators of hip fractures with odds ratios ranging from 1.88 to 2.63 and areas under the ROC curves ranging from 0.663 to 0.740. Among the QUS variables, the SOSP showed the best odds ratio and area under curve. Comparison between the areas under the ROC curve did not show any significant difference between SOSP, BUA and BMD. On the contrary, the difference between SOSC and BMD was significant (P < 0.05). In conclusion, BMD and QUS variables investigated in the current study were significant discriminators of hip fractures. The differentiation of the hip fractures by BMD was significantly better than that of BUA measured at the calcaneus. Moreover, BMD discriminated fractured patients better than BUA and SOS(P), although the difference did not reach statistical significance.

Bladder wall dosimetry for 131I administered activities.

Detailed dosimetric calculations of bladder dose from 131I accumulations are presented, using Monte Carlo simulations and the dynamic bladder model proposed in the recent revision of MIRD Pamphlet No 14. Penetrating radiation and electron dose to the bladder wall inner surface, as well as within the bladder wall, per unit of 131I activity accumulated in the bladder, are calculated for various bladder filling volumes. The effect of backscatter was taken into account for photon dose calculations while electron dose was determined for all the beta spectral components of 131I. Dosimetric results were used to derive simple parameterisation functions of photon and electron dose with respect to bladder filling volume in combination with any bladder physiology model. Calculations of bladder dose per unit of 131I-OIH and 131I-NaI administered activity, using the derived parametrisations, differ by less than 12% from corresponding results given in the recent revision of MIRD Pamphlet No 14.

Estimation of doses received by patients undergoing radiological examinations in Greece.

This study deals with the estimation of doses received by patients undergoing radiological examinations in order to establish diagnostic reference levels (DRLs) within the process of optimisation of patients' exposure in Greece. Six large hospitals in Athens were selected and 385 patients made up the sample. The entrance surface doses (ESDs) to patients undertaking five common X ray examinations (chest, cervical spine, lumbar spine AP and LAT, pelvis) were estimated using both thermoluminescence dosemeters (TLDs) attached to the patient's skin and an ionisation chamber for air kerma measurements. Exposure settings and patient's data were recorded. Results concerning the kilovoltage and focus-to-film-distance (FFD) settings and the ESD values were analysed and compared to those recommended by the EU. Discrepancies in the patient doses and techniques used for the examinations studied were found among the different hospitals denoting the importance of establishing a national quality assurance programme and examination protocols to ensure patient doses are kept as low as possible. All the examinations studied fulfilled the EU recommendations except that for the chest where the doses were considerably higher due to the use of low kVP settings.

Conceptus radiation dose and risk from cardiac catheter ablation procedures.

BACKGROUND: The aim of the current study was to estimate the conceptus radiation dose and risk associated with fluoroscopic imaging during a catheter ablation procedure for supraventricular tachycardia performed on the expectant mother. METHODS AND RESULTS: Exposure parameters and fluoroscopy times for each projection of the cardiac ablation procedure performed in 20 female patients of childbearing age were recorded. Radiation doses for a potential conceptus were estimated by using dose data obtained in anthropomorphic phantoms simulating pregnancy at the first, second, and third trimesters. Dose measurements were carried out using thermoluminescent dosimeters. For a typical examination, the average radiation dose to the conceptus was <1 mGy in all periods of gestation. Average excess fatal cancer was 14.5/10(6) unborn children irradiated during the first postconception weeks. Corresponding values for the second and third trimesters were 30 and 55.7/10(6), respectively. The risk for hereditary effects in future generations was 1.5/10(6) cases for conceptus irradiation during the first postconception weeks. Corresponding values for the second and third trimesters were 3.0 and 5.6/10(6), respectively. Formulas and dose data are presented for estimating the conceptus risk from any technique and x-ray system used for catheter ablation procedures. CONCLUSIONS: A typical catheter ablation procedure results in a very small increase in risk of harmful effects to the conceptus. However, estimation of conceptus dose from catheter ablation procedures is always needed to assess the risk to the individual developing in utero.

Dose constraints to the individual annual doses of exposed workers in the medical sector.

The study is an attempt, within the process of the optimization of radiation protection, to propose constraints to the individual annual doses of classified workers employed in the medical sector of ionizing radiation applications in Greece. These exposed workers were grouped according to their specialties, i.e. medical doctors, technicians and nurses and their occupational category with common or similar tasks, such as diagnostic radiology, interventional radiology, nuclear medicine and radiotherapy. The last 5 years' annual dose distributions of these occupational groups, coming from the National Dose Registry Information System (NDRIS) of the Greek Atomic Energy Commission (GAEC) were analyzed. The proposed dose constraints (DCs) were set at levels, below which the annual doses of the 70 or 75% of the exposed workers per category are expected to be included. At the present stage the derived values may be considered achievable ceiling values referring to acceptably applied practices rather than to optimized ones, taking into account social and economic criteria.

The contribution of hypogonadism to the development of osteoporosis in thalassaemia major: new therapeutic approaches.

OBJECTIVE: The osteoporosis seen in thalassaemia major is of multifactorial origin. The aim of the study was to evaluate the contribution of hypogonadism to the development of this osteoporosis and to assess the efficacy of new sex hormone replacement therapy regimens. DESIGN AND PATIENTS: Sixty-seven patients were studied: 12 were hypogonadal, 32 had been on previous hormone replacement therapy (conjugated oestrogens plus medroxyprogesterone for females, depot testosterone esters for males); 10 had received continuous courses of treatment and 22 3-monthly on/off courses, and 22 were eugonadal without previous replacement therapy. Twenty-seven of the above patients were evaluated prospectively at 16 and 32 months during different therapeutic approaches (12 without treatment, 7 on continuous replacement and 8 on/off schemes followed by continuous therapy during the second observation period). The continuous schemes comprised either transdermal oestradiol (100 micrograms) plus medroxyprogesterone for females or hCG to produce serum testosterone concentrations within normal range, for males. MEASUREMENTS: Bone mineral density (BMD) and bone mineral content (BMC) of lumbar spine and distal end of radius were measured by dual-energy X-ray absorptiometry. RESULTS: Spinal BMD was found to be more than 30% lower than that of controls matched for sex and age with no difference between sexes. Radial BMD was less impaired and showed significantly (P < 0.01) higher levels in males (decrease of 5.8% +/- 2.3, mean +/- SD) than in females (-14.5 +/- 3.4%, mean +/- SD). In the retrospective evaluation it was found that the hypogonadal group had the lowest (P < 0.0001) BMD levels (0.62 +/- 0.01, mean +/- SE) and the highest were observed on the continuous replacement group (0.83 +/- 0.04), whereas the values of the other groups were similar. In a multiple regression analysis model it was found that only sex steroid levels were related to the BMD measurements (for oestradiol t = 2.6, P = 0.01 and for testosterone t = 6.5, P = 0.0001), whereas parameters related to haemolytic anaemia and desferrioxamine treatment were not. In the prospective study the continuous replacement group increased BMD and BMC values more than the on/off treatment courses (P = 0.01). CONCLUSIONS: Hypogonadism seems to play an important role in the development of osteopenia-osteoporosis in thalassaemia major; continuous hormone replacement therapy with transdermal oestrogen for females or hCG for responding males best improves the bone density parameters.

Immunolocalization of transitional cell carcinoma of the bladder with intravesically administered technetium-99m labelled HMFG1 monoclonal antibody.

The aim of this study was the immunolocalization of transitional cell carcinoma of the bladder with a radiolabelled murine tumour-associated monoclonal antibody and the measurement of the absolute uptake of the antibody by the tumour. Fourteen patients with transitional cell carcinoma of the bladder received 3-6 mCi (111-222 MBq) of technetium-99m labelled HMFG1 monoclonal antibody intravesically and one patient, 2 mCi (74 MBq) of iodine-131 labelled 11.4.1, which is a non-tumour-specific monoclonal antibody. Four of the 15 patients were evaluated with single-photon emission tomography (SPET) 1 1/2 to 2 h post administration. All patients underwent transurethral resection of the bladder tumour within 12-20 h following intravesical administration of the radiolabelled antibody. The radioactivity of biopsy specimens from normal urothelium and tumour areas were counted in a gamma counter. The mean uptake of the radiolabelled antibodies from normal and tumour sites was expressed as a percentage of the administered dose per kilogram of tissue. Conventional histology and immunohistochemistry using HMFG1 monoclonal antibody were performed on paraffin sections of the biopsy specimens. Although our results are preliminary, it can be concluded that: (a) bladder tumours are well imaged by SPET when using 99mTc-HMFG1; (b) intravesically administered radiolabelled antibody remains on the bladder tissue and does not escape into the systemic circulation; (c) the wide range of tumour uptake values (0%-9.3% administered dose/kg) observed probably can be attributed to heterogeneity of the antigenic expression of the tumour; (d) values of 99mTc-HMFG1 monoclonal antibody uptake by the tumour do not justify future attempts at radioimmunotherapy.

The effect of hydration on the dose to the urinary bladder wall during technetium-99m diethylene triamine penta-acetic acid renography.

A spherical bladder dynamic model for the estimates of the radiation dose to the bladder walls from intravenously injected radionuclides was implemented to investigate in theory the effect of hydration on the reduction of the bladder dose in technetium-99m diethylene triamine penta-acetic acid (99mTc) DTPA renography. This model gives due consideration to the variation with time of the urine flow rate to the bladder, following a known fluid load. According to the model, the estimated dose depends on the renal function, the fluid load, the time elapsed from the fluid load to the i.v. DTPA injection, the micturition volume and the residual urine volume. Experimental data concerning the values of these parameters for normal individuals were obtained from the literature. Calculations cover the time period from i.v. injection up to the time of the ninth postinjection void. Results show that the patient's condition of hydration is critical for the radiation protection of the bladder. It is shown that optimum combinations of the values of the parameters involved in the calculations exist, which minimize the radiation dose. On the basis of these results, a general protocol is proposed, referring to the hydration conditions under which the renal dynamic study may be normally carried out, with a minimal absorbed dose to the bladder walls (less than 0.045 mGy/MBq).